Gear teeth may be subjected to degradation. Such degradation may be due to any number of factors, such as defects in manufacturing, a breakdown of materials due to use, etc. Current techniques use statistical or time-series features of a time-synchronous average associated with a shaft for a gear of interest. These techniques can detect major faults, but don't typically perform well for earlier stages of gear degradation.
A split torque gearbox (e.g., a planetary gearbox) may share a load among multiple load paths (e.g., multiple parallel load paths). A split torque gearbox may incorporate identical or substantially similar shaft/gear configurations in parallel. Monitoring a vibration associated with split torque gearboxes may be difficult because there may be many identical or substantially similar gear meshes (e.g., the same number of gear teeth, the same shaft frequency). A vibration signal produced by a single faulty gear may be obscured by other healthy gears with, e.g., identical gear mesh frequencies, which can make it difficult to detect and diagnose incipient failures.